On the 1.2x versions that I admin we always Edit Phrase: xenforo_copyright to add "Forum contents copyright<our companies>" after, and in addition to, the Xenforo copyright notice.
But it seems that on the 1.3 beta this change isn't possible. The database/admin cp reflects the change, the forum does not. As if the forum display ignores what's in the database.
Is this a new development, a beta-only thing, or have I just swallowed too much Oxycodone today?